Battery cell, battery, and electric device
By setting a microporous layer on the surface of the negative electrode active material layer to adsorb manganese ions, the problem of battery performance degradation caused by manganese ion dissolution was solved, and the battery cycle performance was improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- QINGTAO (KUNSHAN) ENERGY DEV CO LTD
- Filing Date
- 2025-06-04
- Publication Date
- 2026-06-16
Smart Images
Figure CN224366839U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Technology
[0002] Batteries are widely used in the field of new energy, such as electric vehicles and new energy vehicles. New energy vehicles and electric vehicles have become a new trend in the development of the automotive industry.
[0003] Due to its abundant reserves and low price, manganese-containing cathodes such as lithium manganese oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, and lithium manganese iron phosphate have low maintenance costs, making them a research hotspot.
[0004] However, due to the structural deformation caused by the Jahn-Teller effect, manganese-containing cathodes are prone to manganese ion dissolution during battery charge-discharge cycles. The dissolved manganese ions continuously catalyze the decomposition and regeneration of the SEI film on the negative electrode surface, resulting in a large consumption of electrolyte and thus affecting the battery's cycle performance. Utility Model Content
[0005] Therefore, it is necessary to provide a battery cell, a battery, and an electrical device that adsorbs manganese ions dissolved in the electrolyte on the manganese-based positive electrode sheet, avoids the deposition of manganese ions on the surface of the negative electrode active material layer, slows down the rate of manganese ion catalytic decomposition and regeneration of the SEI film, reduces electrolyte loss, and improves the cycle performance of the battery.
[0006] The first aspect of this application provides a battery cell, which includes: a housing filled with an electrolyte; and an electrode assembly housed within the housing. The electrode assembly includes a positive electrode and a negative electrode, and the electrolyte is used to conduct ions between the positive and negative electrode. The positive electrode is a manganese-based positive electrode, and the negative electrode includes a negative current collector, a negative active material layer, and a microporous layer. The negative active material layer is disposed on at least one side of the surface of the negative current collector, and the microporous layer is disposed on the surface of the negative active material layer for adsorbing manganese ions.
[0007] In some implementations, the pore size of the microporous layer is 0.5 nm to 5 nm.
[0008] In some embodiments, the microporous layer includes: a first microporous layer disposed on the surface of the negative electrode active material layer; and a second microporous layer disposed on the surface of the first microporous layer, the second microporous layer being located on the side closer to the electrolyte; wherein the average pore size of the first microporous layer is smaller than the average pore size of the second microporous layer.
[0009] In some embodiments, the average pore size of the first microporous layer is 0.5 nm to 2.5 nm, and the average pore size of the second microporous layer is 2.6 nm to 5 nm.
[0010] In some embodiments, the microporous layer contains a plurality of interconnected pores, and an adhesive layer is provided on the surface of the pores to fix manganese ions.
[0011] In some implementations, at least a portion of the microporous layer is embedded within the negative electrode active material layer.
[0012] In some embodiments, the thickness ratio of the microporous layer to the negative electrode active material layer is 1:(10~100).
[0013] In some embodiments, the thickness of the microporous layer is 0.1 μm to 30 μm, and the thickness of the negative electrode active material layer is 60 μm to 100 μm.
[0014] A second aspect of this application provides a battery comprising the battery cell provided in the first aspect.
[0015] A third aspect of this application provides an electrical device that includes the battery provided in the second aspect above, the battery being used to provide electrical energy.
[0016] Compared with traditional technologies, this application has at least the following beneficial effects:
[0017] The battery cell provided in this application, by setting a microporous layer on the surface of the negative electrode active material layer, has several advantages. First, the pores of the microporous layer can adsorb manganese ions dissolved in the electrolyte from the manganese-based positive electrode sheet, preventing the deposition of manganese ions on the surface of the negative electrode active material layer, slowing down the rate of manganese ion-catalyzed SEI film decomposition and regeneration, and reducing electrolyte loss. At the same time, the material of the negative electrode active material layer has strong reducing properties, and manganese ions can be reduced after being adsorbed by the pores of the microporous layer, thus confining the manganese ions within the pores and further preventing manganese ions from causing side effects on the surface of the negative electrode active material layer, thereby improving the cycle performance of the battery. Second, the microporous layer on the surface of the negative electrode active material layer can protect the negative electrode active material layer from direct contact with the electrolyte and the generation of side reactions, thereby improving the cycle performance of the battery. Attached Figure Description
[0018] Figure 1 This is a three-dimensional structural diagram of a battery cell according to one embodiment of this application.
[0019] Figure 2 This is a cross-sectional structural diagram of the negative electrode sheet in one embodiment of this application.
[0020] Figure 3This is a cross-sectional structural diagram of the negative electrode sheet in another embodiment of this application.
[0021] Figure 4 This is a comparison chart of the cycle tests of individual battery cells in Example 1 and Comparative Example 1 of this application.
[0022] Figure 5 This is a comparison chart of the cycle tests of individual battery cells in Example 2 and Comparative Example 2 of this application.
[0023] Explanation of reference numerals in the attached figures
[0024] 1. Battery cell; 10. Casing; 20. Electrode assembly; 21. Negative electrode sheet; 210. Negative current collector; 211. Negative active material layer; 212. Microporous layer; 2121. First microporous layer; 2122. Second microporous layer. Detailed Implementation
[0025] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0026] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.
[0027] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0028] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0029] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0030] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.
[0031] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.
[0032] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
[0033] Combination Figures 1 to 3As shown, a first aspect of this application provides a battery cell 1, which includes a housing 10 and an electrode assembly 20. The housing 10 is filled with an electrolyte. The electrode assembly 20 is housed within the housing 10 and includes a positive electrode and a negative electrode 21. The electrolyte is used to conduct ions between the positive and negative electrode 21. The positive electrode is a manganese-based positive electrode. The negative electrode 21 includes a negative current collector 210, a negative active material layer 211, and a microporous layer 212. The negative active material layer 211 is disposed on at least one side of the surface of the negative current collector 210, and the microporous layer 212 is disposed on the surface of the negative active material layer 211. The microporous layer 212 is used to adsorb manganese ions dissolved in the electrolyte from the manganese-based positive electrode.
[0034] The battery cell 1 provided in this application has a microporous layer 212 on the surface of the negative electrode active material layer 211. On the one hand, the pores of the microporous layer 212 can adsorb manganese ions dissolved in the electrolyte from the manganese-based positive electrode sheet, avoiding the deposition of manganese ions on the surface of the negative electrode active material layer 211, slowing down the rate of manganese ion catalytic SEI film decomposition and regeneration, and reducing electrolyte loss. At the same time, the material of the negative electrode active material layer 211 has strong reducing properties, and manganese ions can be reduced after being adsorbed by the pores of the microporous layer 212, so that the manganese ions are trapped in the pores, further avoiding the side effects of manganese ions on the surface of the negative electrode active material layer 211, thereby improving the cycle performance of the battery. On the other hand, the microporous layer 212 is located on the surface of the negative electrode active material layer 211, which can protect the negative electrode active material layer 211 from direct contact with the electrolyte and the generation of side reactions, thereby improving the cycle performance of the battery.
[0035] It is understood that the electrode assembly 20 is the component in the battery cell 1 where the electrochemical reaction occurs. The casing 10 may contain one or more electrode assemblies 20. The electrode assembly 20 is mainly formed by winding or stacking positive and negative electrode sheets 21, and a separator is usually provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets 21 containing active material constitute the main body of the electrode assembly 20, while the portions of the positive and negative electrode sheets 21 without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte.
[0036] In some embodiments, the pore size of the microporous layer 212 is 0.5 nm to 5 nm. Exemplarily, the pore size of the microporous layer 212 can be, but is not limited to, 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, and 5 nm. Within the above range, because its size matches that of manganese ions, it can more effectively capture and adsorb manganese ions in the electrolyte, improving the adsorption efficiency of manganese ions, thereby slowing down the rate of manganese ion-catalyzed SEI film decomposition and regeneration, reducing electrolyte loss, and improving battery cycle performance.
[0037] In some of these implementations, such as Figure 3 As shown, the microporous layer 212 includes a first microporous layer 2121 and a second microporous layer 2122. The first microporous layer 2121 is disposed on the surface of the negative electrode active material layer 211. The second microporous layer 2122 is disposed on the surface of the first microporous layer 2121, and the second microporous layer 2122 is located on the side closer to the electrolyte. The average pore size of the first microporous layer 2121 is smaller than the average pore size of the second microporous layer 2122. Thus, by setting a first microporous layer 2121 and a second microporous layer 2122, with the average pore size of the first microporous layer 2121 being smaller than that of the second microporous layer 2122, the second microporous layer 2122, having a larger pore size, can initially adsorb manganese ions in the electrolyte, while the first microporous layer 2121, having a smaller pore size, can further capture and fix manganese ions. This bilayer structure improves the adsorption efficiency and stability of manganese ions, thereby reducing the deposition of manganese ions on the surface of the negative electrode active material layer 211, slowing down the decomposition and regeneration of the SEI film, reducing electrolyte loss, and improving the cycle performance and service life of the battery.
[0038] In some embodiments, the average pore size of the first microporous layer 2121 is 0.5 nm to 2.5 nm, and the average pore size of the second microporous layer 2122 is 2.6 nm to 5 nm. Exemplarily, the average pore size of the first microporous layer 2121 can be, but is not limited to, 0.5 nm, 1 nm, 1.5 nm, 2 nm, or 2.5 nm; and the average pore size of the second microporous layer 2122 can be, but is not limited to, 2.6 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, or 5 nm.
[0039] In some embodiments, the microporous layer contains a plurality of interconnected pores, and an adhesive layer is further disposed on the surface of the pores to fix manganese ions. The adhesive layer is an adhesive with hydroxyl or carboxyl groups, such as polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), styrene-butadiene rubber latex (SBR), etc. Lithium ions can enter the pores, and the adhesive layer can further enhance the interception and capture ability of manganese ions, thereby improving the interception effect of manganese ions, reducing the damage of manganese ions to the negative electrode, and thus improving the cycle performance and service life of the battery.
[0040] In some embodiments, at least a portion of the microporous layer 212 is embedded within the negative electrode active material layer 211. Thus, by embedding at least a portion of the microporous layer 212 within the negative electrode active material layer 211, the embedded structure increases the contact area between the microporous layer 212 and the negative electrode active material layer 211, improving structural stability and the efficiency of manganese ion adsorption. Simultaneously, it brings the adsorption site of manganese ions closer to the negative electrode active material layer 211, more effectively preventing manganese ions from reaching the negative electrode surface. This reduces the catalytic decomposition of the SEI film by manganese ions, enhances the protection of the negative electrode, and extends the battery's cycle life.
[0041] In some embodiments, the thickness ratio of the microporous layer 212 to the negative electrode active material layer 211 is 1:(10~100). Exemplarily, the thickness ratio of the microporous layer 212 to the negative electrode active material layer 211 can be, but is not limited to, 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90, and 1:100. Within the above range, an appropriate thickness ratio ensures that the microporous layer 212 has sufficient adsorption capacity to capture manganese ions, while avoiding excessive space occupation due to an overly thick microporous layer 212, which would affect the capacity of the negative electrode active material layer 211. This achieves a balance between protecting the negative electrode active material layer 211 from manganese ion damage and maintaining battery energy density, reducing electrolyte loss and improving battery cycle performance.
[0042] In some embodiments, the thickness of the microporous layer 212 is 0.1 μm to 30 μm, and the thickness of the negative electrode active material layer 211 is 60 μm to 100 μm. Exemplarily, the thickness of the microporous layer 212 can be, but is not limited to, 0.1 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, or 30 μm; and the thickness of the negative electrode active material layer 211 can be, but is not limited to, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, or 100 μm.
[0043] In some embodiments, the microporous layer 212 is a hard carbon layer. Thus, by setting the microporous layer 212 as a hard carbon layer, utilizing the microporous characteristics formed by its short-range ordered and long-range disordered graphite-like microcrystalline structure, the hard carbon layer can not only adsorb manganese ions to protect the SEI film and the negative electrode active material layer 211, but also significantly improve the battery's charge-discharge efficiency and cycle performance due to its good conductivity and mechanical stability. Furthermore, the hard carbon layer comprises several hard carbon particles, with pores formed between the hard carbon particles. An adhesive layer is disposed on the surface of the hard carbon particles, constituting an adhesive layer within the pores, which can enhance the interception and capture effect of manganese ions.
[0044] In some embodiments, the negative electrode active material layer 211 is a graphite layer.
[0045] In some embodiments, the negative current collector 210 is a copper foil.
[0046] In some embodiments, the manganese-based positive electrode includes any one of lithium manganese oxide positive electrode, lithium iron manganese phosphate positive electrode, lithium nickel manganese oxide positive electrode, and lithium-rich manganese-based positive electrode.
[0047] A second aspect of this application provides a battery comprising the battery cell 1 provided in the first aspect above.
[0048] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.
[0049] In a battery, there can be one or more battery cells 1. If there are multiple battery cells 1, they can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 1 are connected in both series and parallel. Multiple battery cells 1 can be directly connected in series, in parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 1 is housed in a box. Alternatively, multiple battery cells 1 can first be connected in series, in parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, in parallel, or in a mixed manner to form a whole assembly, which is then housed in a box.
[0050] In some embodiments, the battery can be a battery module. When there are multiple battery cells 1, the multiple battery cells 1 are arranged and fixed to form a battery module.
[0051] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.
[0052] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.
[0053] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.
[0054] A third aspect of this application provides an electrical device that includes the battery provided in the second aspect, the battery being used to provide electrical energy. Thus, the electrical device possesses all the features and advantages of the battery provided in the third aspect, which will not be repeated here.
[0055] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.
[0056] The present application will be further described below with reference to specific embodiments and comparative examples.
[0057] Example 1
[0058] This embodiment provides a single battery cell, which includes a casing and an electrode assembly. The casing is filled with a 1 mol / L lithium hexafluorophosphate electrolyte. The electrode assembly is housed within the casing and includes a positive electrode and a negative electrode. The positive electrode is a lithium manganese oxide positive electrode, and the negative electrode includes a negative current collector, a negative active material layer, and a microporous layer. The negative current collector is a copper foil, the negative active material layer is a graphite layer, and the microporous layer is a hard carbon layer with a pore size of 2.5 nm. The graphite layer is disposed on one side of the copper foil, and the hard carbon layer is disposed on the surface of the graphite layer. By rolling, a portion of the hard carbon layer is embedded into the graphite layer. The hard carbon layer is used to adsorb manganese ions dissolved in the lithium hexafluorophosphate electrolyte from the lithium manganese oxide positive electrode.
[0059] Example 2
[0060] This embodiment provides a single battery cell, which includes a casing and an electrode assembly. The casing is filled with a 1 mol / L lithium hexafluorophosphate electrolyte. The electrode assembly is housed within the casing and includes a positive electrode and a negative electrode. The positive electrode is a lithium iron manganese phosphate positive electrode, and the negative electrode includes a negative current collector, a negative active material layer, and a microporous layer. The negative current collector is a copper foil, the negative active material layer is a graphite layer, and the microporous layer is a hard carbon layer with a pore size of 2.5 nm. The graphite layer is disposed on one side of the copper foil, and the hard carbon layer is disposed on the surface of the graphite layer. By rolling, a portion of the hard carbon layer is embedded into the graphite layer. The hard carbon layer is used to adsorb manganese ions dissolved in the lithium hexafluorophosphate electrolyte from the lithium iron manganese phosphate positive electrode.
[0061] Comparative Example 1
[0062] This comparative example provides a single battery cell, which includes a casing and an electrode assembly. The casing is filled with a 1 mol / L lithium hexafluorophosphate electrolyte. The electrode assembly is housed within the casing and includes a positive electrode and a negative electrode. The positive electrode is a lithium manganese oxide positive electrode, and the negative electrode includes a negative current collector and a negative active material layer. The negative current collector is a copper foil, and the negative active material layer is a graphite layer disposed on one side of the copper foil.
[0063] Comparative Example 2
[0064] This comparative example provides a single battery cell, which includes a casing and an electrode assembly. The casing is filled with a 1 mol / L lithium hexafluorophosphate electrolyte. The electrode assembly is housed within the casing and includes a positive electrode and a negative electrode. The positive electrode is a lithium iron manganese phosphate positive electrode, and the negative electrode includes a negative current collector and a negative active material layer. The negative current collector is a copper foil, and the negative active material layer is a graphite layer disposed on one side of the copper foil.
[0065] Performance testing
[0066] The battery cells of the above embodiments and comparative examples were tested, and the test steps are as follows:
[0067] ① First activate at 0.1C for 2 cycles;
[0068] ② Charge at 1C current to the termination voltage at a temperature of 45℃±2℃, cut off current 0.05C, and let stand for 30 minutes;
[0069] ③ Discharge at 1C until the final discharge voltage (2.75V), record the discharge capacity, and let stand for 30 minutes;
[0070] ④ Cycle ② to ③, test the battery's cycle capacity retention rate, and the test results are as follows: Figure 4 and Figure 5 As shown.
[0071] Combination Figure 4 and Figure 5 As shown in the comparison of Examples 1-2 and Comparative Examples 1-2, it can be seen that the battery cell provided in this application uses a microporous layer to adsorb manganese ions dissolved in the electrolyte by the manganese-based positive electrode sheet, thereby improving the cycle performance of the battery.
[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0073] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A battery cell, characterized in that, include: The casing is filled with electrolyte; as well as An electrode assembly is housed within the housing, the electrode assembly comprising a positive electrode and a negative electrode, and the electrolyte is used to conduct ions between the positive electrode and the negative electrode; The positive electrode is a manganese-based positive electrode, and the negative electrode includes a negative current collector, a negative active material layer, and a microporous layer. The negative active material layer is disposed on the surface of at least one side of the negative current collector, and the microporous layer is disposed on the surface of the negative active material layer. The microporous layer is used to adsorb manganese ions.
2. The battery cell according to claim 1, characterized in that, The pore size of the microporous layer is 0.5 nm to 5 nm.
3. The battery cell according to claim 2, characterized in that, The microporous layer includes: A first microporous layer is disposed on the surface of the negative electrode active material layer; and A second microporous layer is disposed on the surface of the first microporous layer, and the second microporous layer is located on the side closer to the electrolyte; The average pore size of the first microporous layer is smaller than the average pore size of the second microporous layer.
4. The battery cell according to claim 3, characterized in that, The average pore size of the first microporous layer is 0.5 nm to 2.5 nm, and the average pore size of the second microporous layer is 2.6 nm to 5 nm.
5. The battery cell according to any one of claims 1 to 4, characterized in that, The microporous layer contains a number of interconnected pores, and an adhesive layer is provided on the surface of the pores to fix manganese ions.
6. The battery cell according to any one of claims 1 to 4, characterized in that, At least a portion of the microporous layer is embedded within the negative electrode active material layer.
7. The battery cell according to any one of claims 1 to 4, characterized in that, The thickness ratio of the microporous layer to the negative electrode active material layer is 1:(10~100).
8. The battery cell according to claim 7, characterized in that, The thickness of the microporous layer is 0.1 μm to 30 μm, and the thickness of the negative electrode active material layer is 60 μm to 100 μm.
9. A battery, characterized in that, Includes the battery cell described in any one of claims 1 to 8.
10. An electrical appliance, characterized in that, Includes the battery of claim 9, the battery being used to provide electrical energy.